The question you have asked is the bases for a good PMP article. Swarms After Treatments. Best I know there is little scientific data to prove this happens as a result of the treatment or not. In the field we have all experienced swarm within six week of new applications, and for whatever treason these are the first to swarm in the next swarm period either fall or early spring/summer depending on where you are located in relationship to the equator.

Old information’s lives forever weather right or wrong. Backing up to chlordane and heptachlor (hep·ta·chlor), the emulsifier in both products was xylene, this created vapor pressure, so when using either product singly or when they were combined like Orkil (Chlorhepton) or Termide you could get a flushing action from the heptachlor that has a vapor pressure of 10 which is much higher than chlordane.

Vapor from Dursban also had a vapor pressure that caused a flushing action after application. When Dow switched to water base and change the dilution this problem stopped.

All of the first generation pyrethroids also used xylene as their main emulsifier and they even created more vapor resulting after treatment swarms.

When termites swarm in structures in the same place as last year or swarm season. That generally mean for whatever reason that group (colony) was missed last year and the exception can be they found a moisture supply above ground, examples shower stall, wax ring, leaking, tub or shower, chimney, roof, pipe protruding through the sealing, clogged gutters or down spouts, ice dam, and just plain roof leaks at nail backup’s.

Another Look at Crawlspace Remediation

Four Foot Basement
May 29, 2014PMP Magazine October 2014 Article
When we first looked at the possibility of closing crawlspaces, I was sure that going to be a bad idea. Based on all of our training and experience up to then the best way to control moisture was to install aground cover of 70 – 80 percent of the ground space and introduce more air so we the industry started installing more vents, introducing Temp -Vents Automatic Vents System and Power Vents became common. That worked until we go into the 1990.
As home owners reacted to the need to save energy tighter construction became the thing in most all structures. More insulation, better sealed walls, windows and doors. The tighter the house go the more the crawlspace became a bigger problem leading to huge moisture problems, fungus, mold, mildew, insects, foul odors, and structure damages.
Crawlspace remediation became the best solution for dealing with these problems, but only if done properly so over the last ten years we have experienced lots of situation that has led to some improvements in the process that we now know must be considered.Dehumidifier
First we need to look at what are the requirements to prevent excess moisture that leads to higher than wanted relative humidity. Moisture below 20 percent inside the structural timbers in crawlspace and humidity below 60 percent will not form mold are rot due to decay fungus. Best setting need to be lower year round so between 10 and 20 moisture and 40 and 60 humidity is in the safe range.
Due to today’s tight construction some type of dehumidification is recommended in all areas. Some of the newer whole house air-conditioning units offers built in deification as a part of the unit providing the unit is large enough to include the volume of the crawlspace. Closed crawlspace can also cause a problem when ground water comes in the crawlspace or some leak accurses allowing water to collect on top of the ground cover. Without some way to dissipate the excess water enactive fungal spores with germinate and the problem starts all over without proper provisions with dealing with the excess water. That simply is why it is recommended to install a dehumidifier in every closed remediated crawlspace and a water alert system available through your supplier.Ground Cover
Next is ground cover, there are many types and manufactures out there that make excellent ground covers. Ground cover is not just a piece of polyethylene you want it to do the job and improve the appearance of the crawlspace. The objective is not just to cover, but is to seal the space at 100 percent so rising humidity does not come inside the space.
The thicker the ground cover is the better, current the millage runs from 6 mil, all the way up to 24mil. With 8 to 12 reinforced being the most used. Colors all the way from clear to white and with and without liners to go under the cover.
Joints have to be sealed with at least one foot of lap, two foot is recommended. Seal can be adhesive sprays or best double sided four inch tape. Pears also need to be covered and sealed in the same manor.Foundation Walls
Regardless of foundation wall type brick, block, rock, or poured concrete they need to be sealed. Leaving an inspection area of four inches at top and bottom of the wall for termite and other inspections. Vents, opening around utilities entries and foundation cracks. The smallest opening will allow outside hot air to find it a way into the crawl space bringing water with it seeking cooler surfaces referred to as perk point.
The next point to consider is insulating inside of outside foundation walls with Foam Insulation Board. Now several manufacturers and distributors have a product that is treated with borates for the control of insects and installed correctly has shown not to increase the accordance of subterranean termites. Check with your crawlspace supplier for a list of the new products.Wood treatment
Wood treatment is a vital part of the crawlspace remediation program. Mold spores should not be left on the substructure they will go dormant when the moisture is reduced, but as soon as the moisture returns for any reason to 20 plus percent the spores will reactivate as they were before the remediation. After cleaning the wood needs to be treated with a fungicide and water repellent to control any existing fungus and prevent it in the future.Inspection
Follow up inspection is needed to verify the space is dry and the humidity and moisture are at expected levels.
Remediation of the crawlspace saves energy and improves the quality of the whole structure.

When I started working in the Pest Control Industry in 1961 it was worth less than ½ billion. I like to believe that some of the services I developed or was a major contributor to developing and starting helped it grow to be the 7.2 billion dollar industry it is today. A few of the services I had a large part in developing are outside services, fourth barrier (use of Borates), foam termite treatment, bait development in combination with Dow and FMC. See the article by the Pest Management Professionals below:

MENDHAM, NJ—According toSpecialty Product Consultants’ Gary Curl, the U.S. structural pest control industry generated an estimated $7.213 billion in total service revenue in 2013, a 5.9 percent increase from the $6.815 billion measured in 2012. The Top 4 U.S. service providers, Orkin, Terminix, Ecolab and Rentokil, represented nearly 45 percent of the total industry revenue for the termite and general pest control market segments this past year.

Rodent control service revenue was particularly robust this past year. In the Northeast United States, pest control companies reported that their highest percentage of revenue earned was from controlling mice and rats.

“We believe ‘Superstorm Sandy’ that hit the East Coast in late October of 2012 may have displaced rodents, resulting in an increased need for control efforts in the region this past year,” Curl says.

Total manufacturer level revenue for rodenticides increased nearly 10 percent this past year. Three active ingredients — bromadiolone, difethialone and brodifacoum — accounted for more than 85 percent of total U.S. rodenticide sales.

Nationwide, 86.5 percent of the respondents said their company treated for bed bugs. Six of ten respondents primarily relied on insecticide treatments to control bed bugs.

One in five (19.9%) relied on heat or steam treatments. Service revenue derived from controlling bed bugs increased more than 11 percent from the prior year, bringing the total revenue earned from controlling this pest to nearly $450 million. Single-family

homes and apartments were the primary leading types of accounts pest management professionals (PMPs) treated for bed bugs, followed by hotels and motels.

Nationwide, PMPs reported good growth in both residential (+4.6%) and commercial (+6.5%) service revenue from the prior year. Total service revenue generated from termite work improved, as well.

The South Central (TX, LA, OK, AR) region of the U.S. reported the weakest swarm season with nearly two-thirds (65.4%) of the respondents reporting a “much weaker than normal” or “weaker than normal” swarm season. Nevertheless, there was a nearly 4 percent increase in the number of post-construction termite jobs completed.

Improved pricing actions raised the average post-construction job 5.4 percent to $836.04 per treatment this past year. Pre-construction termite treatment revenue increased 8.1 percent on the strength of an 18.5 percent increase in privately owned new housing unit construction “starts.” Nearly 45 percent of all privately owned housing “starts” in the U.S. received a pre-construction termite treatment this past year.

Total manufacturer level revenue increased 5.7 percent this past year, to more than $515 million. After a number of challenging years for suppliers, this brings total manufacturer level sales revenue back to the same level experienced more than 10 years ago (2003).

Nearly nine of ten (85.8%) operators surveyed said they were aware of the U.S. Environmental Protection Agency’s (EPA’s) national initiative, which changed the outdoor use directions for pyrethroid insecticide products. More than half (51.1%) reported that they had stopped power spraying pyrethroids and switched to using a “backpack” or smaller sprayer. More than one-quarter (28.9%) said they had not been affected yet, as they had “stocked up” on older labeled products.

The 2013 season market report is the 14th edition of A Strategic Analysis of the U.S. Structural Pest Control Industry. A total of 800 owners or managers of pest control companies were surveyed for this study. The market report forecasts pest control service revenue through 2015, and pesticide product category sales through 2018. The impact of the commercial and residential real estate market, mosquito and wildlife management services, changes in distribution, and PMPs’ outlook for 2014 are just a few of the topics analyzed in this year’s report.